A navigation system performs travel guidance for enabling a user to easily and quickly reach the selected destination. A typical example is a vehicle navigation system where a vehicle is equipped with a navigation function to guide a driver to a destination through a calculated route. Typically, the navigation system displays a map image while superimposing thereon a mark representing the current location and notifies the user which direction to turn at an intersection to reach the destination.
FIGS. 1A-1H show an example of overall procedure and screen display involved in the navigation system for route guidance to a destination. FIG. 1A is an example of locator map screen of the navigation system when the destination is not specified. Typically, the navigation system displays a street on which the vehicle (current vehicle position VP) is running on a map image and a name of the street. Other information such as a north pointer NP, a map scale and a current time may also be illustrated on the display screen.
FIGS. 1B-1F show an example of process for specifying a destination in the navigation system. When selecting a “Destination” menu on a main menu screen of FIG. 1B, the navigation system displays an “Find Destination By” screen as shown in FIG. 1C for specifying an input method for selecting the destination. The “Find Destination By” screen lists various methods for selecting the destination. This example includes the methods of “Address”, “Intersection”, “Point of Interest”, “Recent Route”, “Address Book”, and “Today's Plan” which are well known in the art.
When selecting, for example, the “Address” method in FIG. 1C, the navigation system displays a keyboard screen in FIG. 1D. Suppose the user inputs an address “2525 W. Carson” of a shopping mall, the navigation system displays a “Confirm Destination” screen such as shown in FIG. 1E. If the name and address on the screen shows the correct destination, the user enters an “OK to Proceed” key to proceed to the next procedure.
In FIG. 1F, the navigation system calculates and determines a route to the destination, i.e., the address “2525 W. Carson”. The navigation system determines a route to the destination based on, for example, the quickest way to reach the destination, the route using many free ways as possible or the route without using toll road, and the like. In this example, the navigation system displays a progress scale of the calculation of the route.
Once the route to the destination is determined, the navigation system starts the route guidance as shown in FIG. 1G for guiding the user to the destination. Typically, the navigation system shows the intersection which is highlighted to show the next turn and a direction of the turn. Such route guidance by the navigation system is also accompanied by voice instructions.
The navigation system measures a distance to the current destination to detect whether the destination is within a predetermined range such as within 100 meters. When the user approaches the destination within such a predetermined distance, the navigation system indicates that the destination “Dest” is ahead as shown in FIG. 1H. The navigation system detects the actual arrival based on various factors such as the engine stop.
As noted above, a process of entering a street name (address) is frequently needed when setting a destination in the navigation system. FIGS. 2A-2D are display examples of input screens that accept the user's input of a street name through a full name method. As shown, through a key board screen of FIG. 2A, the user has entered “N MAIN” in the street name field. As a result, the navigation system lists the matching entries that match the user's input “N MAIN” as shown in FIG. 2B. The list shows matching entries “N MAIN”, “N MAINE”, “N MAINLAND”, “N MAINWARD” all of which include “N MAIN”. Since the user has input the prefix “N”, all of the entries start with a letter “N”.
Suppose the user really wants to find an address “10605 E MAIN AVE” in the city of “PALM SPRINGS” but has selected the entry “N MAIN” in FIG. 2B because it was not certain whether it starts “N” or “E”. Then, the user enters a house number “10605” for the street name “N MAIN” as shown in FIG. 2C. As a result, two matching entries located in “GARDEN GLOVE” and “SANTA ANA”. However, since the prefix “N” is incorrect, the address “10605 E MAIN AVE” in “PALM SPRINGS” intended by the user has not come out by this search.
Although the full name search is direct and intuitive for an inexperienced user, it requires an accurate input of a prefix, suffix and base name. There is another method for inputting a street name in which a user can input a base name of the street without including a prefix or a suffix of the street name. The base name input method is convenient since the user can only remember the base name accurately. However, because it is not direct and intuitive, inexperienced users sometimes do not know such an input method. Therefore, there is a need of a more flexible way of searching a street name for a navigation system which allows both the full name input method and base name input method in the same input field on the screen.